Measuring device



c. 'r. ALLCUTT V MEASURING DEVICE Filed Feb. 5. 1923 WITNES'SEY INVENTOR Chester .TA //0 0H W BY Patented Oct. 12, 1926. I i p i p I UNITED *srAr'Es PATENT c tric-E.

cnnsrnn 11.4mm,onmswmn, PENNSYLVANIA, assI GNoRjp wnsrr c- House ELECTRIC a MANUFACTURING COMPANY, A CORPORATION or PENNSYL- ianisonnfe befits; mummifiedFebruary 3, 1923. Serial mama,

My invention relates'to measuring devices taining the indicatirg'member in its position and particularly to means for facilitating of last indication or, as in a flashover test 55 the'taking' of measurements therewith. for an insulator, the position indicating the H The obJect ,of my invention is to provide voltage value at which the'insulator flashed.

I an electrical measuring instrument that Theholdingmeansis'also'adapted toauto shall be held intheposition indicating the matically release the meter element when value of the QquaHtityeXiSting at the time energized for a subsequent test, so that the theinfluence thereo is removed and that operator is free to direct'his'attention to the shall thereafter be automatically conditioned object to betested' rather than to the'testin'g toresume its 'indi'catingfunction. Instrument.

' In thepriorart, it has been usual, as in The single figure of the accompanying maximum demand meters, to provide a fricdrawing is a diagrammatic view of'a system 65 tioiially pivoted pointer that is moved by in wh ch my invention is embodied. another pointer actuated directly by the A high potentialinsulator 1 isconnected,

meter mechanism. This construction per.- atone terminal, to aground connection G mits the maximum demand pointer to reand, at its other terminal, toone terminal main in its'maximum position until it is of the high-voltagesecondarywinding2of 7t) reset by hand, and illustrates one form of a transformer 3, the other terminal of the meter known to me, which holds orretains winding)? of which is also grounded.

an indication after theinfluence causing it The low tension primary winding 4 of the has been withdrawn. transformer 3 is connected to supply con- However, such an arrangement is more ductors 5 through a circuit interrupter 6 adapted for instruments having considerh t 15 adapted to b opened by an electroable torque, and is ordinarily not employed magnet 7 connected in series with acurrent 26 in very sensitive instruments wherein the transformer 8.

pointer or other indicating member should A voltmeter 9, preferably graduated in oppose, as little as possible, the influence terms of the voltage on the high-tension to causing it to indicate. side of the transformer 2, 1s connected by In conducting certain electrical tests, such leads 10 across the conductors 5. y

so as determining the corona-forming and A shaft 11, that may constitute a part of,

flashover voltage values of a high-potential or be connected to, the movable element of insulator, it has been usual to employ a the meter 9, is provided with a brake drum, 8:)

sensitive voltmeter of the ordinary type, the or other suitable device 12, for co-operation pointer of which rapidly returns to the zero with aholdmg or locking member 13. The

5 iti n, wh th i flu n causing it to latter is adapted to be actuated by an elecdi t i e oved tromagnet 14 that is connected in the cir- Thus, the operators attention must be dicult of the transformer 8 and is biased rected to the instrument in order to deter. to operative or holding position, by a spring mine the flash-over voltage because, at this 15 against the action of the magnet 14.

40 voltage, the instrument circuit is broken In operation, when the circuit interrupter and the pointer returns to zero position. 6 is closed, the electromagnet 14 disengages It is highly desirable that the operator, the member 13 from the member 12 to thus in such tests, be free to study the character permit the instrument 9 to operate in a and location of corona, as well as the parusual manner.

45 ticular nature of the flashover arc,but as When an arc occurs across the terminals above pointed out, he cannot do this with a of the insulator 1, the high-tension winding usual voltmeter and at the same time de- 2 is short-circuited to cause a rush of curtermine the flashover voltage, without the rent in the conductors 5. This action causes aid of an assistant. the electromagnet 7 to automatically trip the 5 In practicing my invention, I provide a circuit interrupter 6 and to thus (ls-energize measuring instrument having a normally the electromagnet 14 which, when so defreely movable element and automatically energized, permits the member 13 to engage actuated braking or holding means for rethe member 12 to hold the movable element of the meter 9 in the position indicating the value of the voltage which caused the insulator to break down.

The device of my invention desirably facilitates such tests and requires no additional attention on the operators part, after being initially connected in circuit.

While I have shown and described a particular form of my invention, changes may be elfected therein Without departing from the spirit and scope thereof, as set forth in the appended claims.

I claim. as my invention:

.1. The combination with an electric circuit, a circuit interrupter therefor and an indicating member operatively connected thereto, of means responsive to the opening of said circuit by said interrupter for stopping and holding the indicating member at a predetermined indicating position and responsive to the closing of said circuit by the interrupter for releasing the indicating member to resume its indicating function.

2. The combination with a measuring instrument, and a movable lndicating member therein responsive to conditions in a circuit, of a device responsive to the opening of said circuit for stopping the indicating member and to the closing of the circuit for releasing the indicating member.

3. The combination with a measuring instrument, and a movable indlcatlng member therein responsive to conditions in a circuit, of an electromagnetic device controlled by the opening of said circuit for stopping the indicating member and to the closing of the circuit for releasing the indicating member.

4. The combination with a circuit, a circuit interrupter and indicating means, of means for automatically operating said interrupter to its open position in accordance with a predetermined circuit condition and for retaining said indicating means in condition to subsequently indicate the value of a quantity of the circuit existing at approximately the time of the interruption.

5. The combination with a circuit, a circuit interrupter and indicating means, of an auxiliary circuit responsive to mined condition in said first circuit and including means for actuating said interrupter and for controlling said indicating means.

6. The combination With a circuit, a circuit interrupt-er and indicating means, of an auxiliary circuit responsive to a predetermined condition in said first circuit and including means for actuating said interrupter and means for retaining said indicating means in the condition thereof at the time of actuation of said interrupter.

In testimony whereof, I have hereunto subscribed my name this 26th day of Jana ary, 1923.

CHESTER T. ALLCUTT.

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